Computer hackers sympathetic to the Syrian government of Bashar Assad launched simultaneous attacks Tuesday, disrupting websites operated by The New York Times and Twitter.

As of Wednesday afternoon, some online New York Times readers in the United States were still unable to click onto the paper’s website.

A shadowy group of cyber-hackers calling themselves the Syrian Electronic Army took credit for the attacks. The outfit has previously claimed responsibility for attacks aimed at other media it regards as sympathetic to Syrian rebels now in their third year of an armed uprising against the Assad regime in Damascus.

“The Syrian Electronic Army is something quite substantive,” said Ron Deibert, a professor of political science at the University of Toronto and author of Black Code: Inside the Battle for Cyberspace. “They are not individuals working in some basement.”

In past attacks, the SEA has tended to exploit human error rather than technical glitches to gain access to private online accounts, and that seemed to be the case in Tuesday’s attacks, which targeted an Australian company called Melbourne IT that registers online domain names such as nytimes.com. The hackers apparently tricked several employees of a company under contract to the Australian firm into revealing secret log-in info, a hacking technique known as “phishing.”

The hackers then tampered with information contained in the registry — for example, by directing New York Times users away from the paper’s website.

Twitter service was also affected but to a lesser degree.

“It goes to show that cyber warfare is going to be a more prominent feature of how battles are won,” said Bessma Momani, a political science professor at the University of Waterloo.

Previously, the Syrian group has claimed credit for attacks carried out against websites operated by National Public Radio, The Washington Post, the BBC and Al Jazeera English, among other media outlets.

Its most notorious attack to date was an assault in April against the Associated Press and its Twitter account. A fake email purporting to be from The Washington Post duped several AP employees into sharing their Twitter log-in information.

“These are the kind of tricks they use to take control of different accounts,” said Luis Corrons, technical director of Panda Security, a Spanish computer security company.

He said it would be difficult to determine the physical whereabouts of the SEA hackers.

“They will be using computers that are not their own,” he said, “and they will also be using VPNs.” Virtual Private Networks are systems employed by some computer users to hide their physical location by making it seem they are somewhere else, in a different country or even a different continent.

“They could be anywhere,” said Deibert, who has studied the SEA for several years, “but we were able to triangulate some of these people and trace them back to Damascus. A good portion of them are in Damascus.”

In the past, he said, the servers used by the SEA were hosted on computers belonging to a Damascus cyber-club called the Syrian Computer Society, which counts Assad himself among its former presidents.

“I think there’s no surprise they have close ties to the regime,” said Momani.

Although the group’s attacks can be damaging to their online victims, Momani said they don’t really provide much direct benefit to Assad or his government.

“In terms of really having an impact, no,” she said. “More than anything else, it feeds the ego of the Syrian regime.”